Unmount paths even on error for koa-mount

index.js.diff

58c58,68
<     await downstream(ctx, async () => {
---
>     try {
>       await downstream(ctx, async () => {
>         ctx.path = prev;
>         try {
>           await upstream();
>         } finally {
>           ctx.path = newPath;
>         }
>       });
>     } finally {
>       debug('leave %s -> %s', prev, ctx.path);
60,65c70
<       await upstream();
<       ctx.path = newPath;
<     });
< 
<     debug('leave %s -> %s', prev, ctx.path);
<     ctx.path = prev;
---
>     }